Physically crosslinked gelatin bio‐inks with enhanced printability, degradation and mechanical robustness for multi‐modal bioprinting

Abstract 3D bioprinting is a transformative technology for fabricating biomimetic tissue constructs with significant potential in tissue engineering and regenerative medicine. However, developing sustainable bio‐inks that achieve good printability, mechanical strength, and stability under physiological conditions without costly and time‐consuming chemical modifications remains a major challenge. In this study, we present a cost‐effective and sustainable physically crosslinked gelatin‐based bio‐ink (Gel‐X) composed of gelatin, gellan gum, and Laponite XLG for multi‐modal bioprinting. The composite Gel‐X bio‐ink is prepared in a straightforward and rapid manner (∼1 h) by simply stirring the different polymers in deionized water, eliminating the need for chemical crosslinkers. This formulation offers improved printability, mechanical properties, and controlled degradation and dimensional stability. Notably, the incorporation of Laponite XLG strengthens the gel network, further improving the structural integrity and mechanical robustness over time. Our results demonstrate that the cell‐laden Gel‐X tissue constructs maintain their structural integrity and robustness under physiological conditions, effectively addressing the rapid degradation and poor mechanical performance associated with conventional physically crosslinked bio‐inks. Furthermore, Gel‐X tissue constructs exhibit good biocompatibility, enabling the fabrication of highly complex and robust 3D structures suitable for bioprinting applications. By eliminating the reliance on chemical crosslinkers, Gel‐X bio‐ink provides a sustainable solution for advanced multi‐modal bioprinting. This innovation not only overcomes existing limitations in bio‐ink design but also broadens the accessibility and utility of 3D bioprinting.